Sharpener for lawn-mowers.



G. W. MILLER.

SHARPBNBR POR LAWN MoWBRs.

` APPLICATION FILED APR. 11. 1913.

1,091,759. Patented Mar.31,1914

@Mom/160% wh/1MM@ @07196 Z6 7l.

@56.74% @'22 g. i 5 ...M/140%. 53* Wx GEORGE W. MILLER, OF SANTA MONICA,CALIFORNIA.

SHARPENER FOR LAWN-FLOWERS.

To all whom t may concern Be it known that I, GEORGE W. MILLER, acitizen of the United States, residing at Santa Monica, in the county ofLos Angeles and State of California, have invented certain new anduseful Improvements in Sharpeners for Lawn-Mowers, of which thefollowing is a specification.

This invention relates to Sharpeners for lawn mowing machines, and itsobject is to provide an attachment for that class of machines whichemploy a series of knives attached to a revolving wheel to coact inshearing contact with a stationary blade, whereby the revolving knivesmay be sharpened, or the revolving knives and the stationary blade maybe sharpened at the same time by merely running the machine.

To this end, my invention consists in the construction and combinationof parts forming a Sharpener for lawn mowers hereinafter more fullydescribed and particularly stated in the claims, reference being had tothe accompanying drawings, in which:

Figure 1, represents my lawn mower Sharpener attached to an invertedlawn mower as seen in longitudinal, vertical section partly in sideelevation at line x-m, Fig. 2. Fig. 2 is a plan view of the sharpenerremoved from the mower. Figs. 3 and 4 represent modications of thesharpener in vertical section. Fig. 5 represents in longitudinalvertical section a modification of the Sharpener in position to sharpenthe revolving knives only.

Numeral 1 represents one of the drive wheels of a lawn mower, 2 a sideportion of the frame, 3 the rear roller mounted in a bearing 4. Wheelarms 5 mounted on a shaft 6 to be revolved in any usual manner by theaction of the drive wheel 1 carry knives 7 with their edges in thedotted circle 37 t0 coact in shearing contact with a stationary blade 8.The blade 8 is fixed to the rock-bar 9 in any usual manner, as by screws10. The rock-bar is pivoted at 11 to the frame 2 and is adapted to berocked by means of adjusting screws 12 passing through a ledge 13 of theframe, in order to tip the edge of the blade 8 to or from the path 37 ofthe knives 7, as may be required. The handle 14 may be considered asturned over backward and resting on the ground.

So far this description represents what is common in lawn mowers. Mysharpening device shown in Fig. 2 has a base plate 16 Specification ofLetters Patent.

Application led April 11, 1913.

Patented Mar. 31, 19,14.

Serial No. 766,520.

adapted to be placed directly upon the face of the blade 8 and to bethere secured by means 0f the blade screws 10 passing through slots 15in the said plate. A grinder 17 of some kind of grit, such as corundum,emery or stone, is supported in a carrier 18, which is provided withrearward extending-arms 19 that are pivotally hung in pairs of ears 20of the plate 16. Springs 21 are secured by means of screws 22 to one ofeach pair of ears 20 to bear their free ends upon ledges 23 of thecarrier 18, whereby the grinder 17 is forced, with yielding pressure,down toward the path of the revolving knives 7, but the downwardmovement is limited by adjusting screws 24, which are threaded throughthe arms 19 and bear their points upon the plate 16. By this means thegrinder may be located adjacent to, that is, just touching, the circularpath 37 of the knives. To preyent the grinder from chattering in itscarrier and thus gradually working itself loose, I interpose a packing25 of soft, cushion-like material, such as felt, on one side, and on theother side I interpose packing 26 of lead, soft iron or other materialthat the screws will indent, between the grinder 17 and its bindingscrews 27. This packing prevents the screws from digging holes in thegrinder and permits the grinder to be accurately set in the firstinstance to just touch the knife edges throughout their length, and thento very firmly bind it against the cushion 25.

In the modification shown in Fig. 3 the grinder 28 is held directly inthe body 29 and is impelled downward by springs 30, whose downwardmovement is limited by screws 31, which are threaded through them andbear upon the body 29. This modification and the one shown in Fig. 4 areprovided with slots, as shown at 15, Fig. 2, for attachment to themachine directly upon the blade, as described relatively to base plate16.

In the modification shown in Fig. 4 the grinder 32 is fitted to slide inthe body 29, but it is fastened to a carrier 33 which is pivoted at 34to a spring 35, through which an adjusting screw 31 is threaded andbears on the body 29, as in Fig. 3; and both of these springs 30 and 35are secured to the body in like manner by screws 36.

The modification shown in Fig. 5 represents its grinder 38 secured to aspring 39 by means of an intermediate block of wood 40,

which may be secured to the grinder in any The features in common in thefour forms/ shown are securing the body of the device directly upon theface of the lawn mower blade, and bringing the grinder in contact withthe revolving knives at a point directly in front of the fixed blade andadapting the grinder to grind both the rotary knives and stationaryblade at the same time, as shown in Fig. 1, or to grind `only the rotaryknives, as shown in Fig. 5.

. In operation the grinder should be adjusted to barely touch the wholelength of the revolving blades, then the machine should be drawn overthe ground in the direction to revolve the knives forward as in mowing.As the grinding of the knives progresses it may be seen in Fig. 1 thatthe stationary blade is also being ground. This is due to particles ofgrit being carried from the grinder to the blade bythe knives andwearing on the blade; the grinder being located so near the blade thatits grit is not lost while the knives pass from grinder to blade. Byadjusting the screws 24 the grinder may be set more and more down untilthe knives are given perfect edges, andrby means of the rocking screws12 the blade may also be brought more and more toward the path 87 of theknives to maintain perfect shearing contact with them until it will alsobe given a perfect edge. It will be understood that when the grinderbecomes worn away until the carrier 18 hits down on the plate 16 thecarrier may be again raised by the screws 24, and by loosening thescrews 27 the grinder may be let down for a new lease of service.

In Fig. 5 the blade 8 is tipped up away from thepath 37 of'the knives,while the grinder 38 is set to act on the knives only. In this positionthe particles of grit are carried past the blade 8 without touching it.

I claim:

1. In a Sharpener for lawn mowers of the class described, a grinder aslong as the rotary knives; a base plate and means for securing itdirectly upon the face of the stationary blade, and means adjustablyconnecting the grinder and the base plate whereby the grinder may beheldnear to the edge of the blade while both the blade and grinder aretangent to the circle of the rotary knives. 2. In a Sharpener for lawnmowers of the class described, a base plate and means for securing itdirectly upon the face of the stationary blade; a grinder as long as therotary knives; means connected with the plate for holding the grinder infront of the said blade; springs coimected with the plate and acting topress the grinder down in front of the blade, and adjusting screws forlimiting the action of the springs.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE W. MILLER. Witnesses:

H. E. HUDSON, F. J. TowNsEND.

Copie of this patent may be obtained for ve cents each, by addressingthe "Commissioner of Patenti,

Wa:11ington,D. G."

